A base 328i costs roughly $37K The hybrid starts at essentially $50K. Now before I even pick up my handy calculator, I can tell you it's going to take a long damn time or a huge increase in the price of gas to make up $13K.

So, if the hybrid gets 100 miles to the gallon, you need 100 gallons to go 10,000 miles. Gas is about $4/gallon, so it'll cost you $400 to drive those 10,000 miles. Let's say the 328 gets 25 miles to the gallon. You then need 400 gallons of gas to drive 10,000 miles, and that'll cost you $1600 at $4/gallon. So you will be recovering $1200/year in gas costs if you continue to drive 10K miles a year and gas remains at $4/gallon (For the past several months, I've actually been paying $3.51/gallon for my 93 octane, but I can do the math in my head more easily at $4/gallon.) At that rate, it'll take you 10.83 years to recover the cost.

Even if you double the price of gas to $8/gallon, it'll take you over five years to recover the premium you paid for getting the hybrid. Admittedly, I didn't consider any tax credits, loan interest, and whatnot, but I think you see the point, particularly since the hybrid gets nothing even close to 100/mpg.

Until the cost of a hybrid can be recouped in three or fewer years, there'll be little reason to buy one.

The recovery rate is:
Directly proportional to the price of gas
Indirectly proportional to the non-hybrid's fuel economy
Directly proportional to the hybrid's fuel economy

Not that your math is off but why are you comparing it with a base 328?

The car has the same performance as a 335i (even more HP/TQ) which has a base of $42,800 vs the active hybrid base of $49,300. Thats only a difference of $6500.